Domain structure features of epitaxial PbTiO3 thin films prepared by MOCVD

摘要

Ferroelectric oxide thin films have attracted great interest in recent years because of their potential applications in numerous electro-optic, pyroelectric, acousto-optical, and nonvolatile memory devices, and a variety of methods such as sputtering, laser ablation, and MOCVD has been used for preparation of the films. Among these ferroelectric materials, the PbTiO(sub 3) thin film has been extensively studied because of its small dielectric constant, large spontaneous polarization, small coercive field, and high Curie temperature of (approximately)500(degrees)C. However, very little work has dealt with the detailed structural properties of the films. In this work, we have prepared epitaxial PbTiO(sub 3) thin films by MOCVD and performed some detailed studies on the structure of the films, particularly those related to the twin domain structure, using X-ray diffraction technique. Based on the comparison of the domain structure features of the films grown at above Curie temperature with those of the films grown at below Curie temperature as well as of bulk PbTiO(sub 3) single crystal, a model is proposed to explain our experimental results. (ERA citation 17:016105)